import java.util.Scanner;

public class uxid {


        public static void main(String[] args) {
            Scanner scanner = new Scanner(System.in);
            int n = scanner.nextInt();
            int q = scanner.nextInt();
            int[] arr = new int[n+1];
            for(int i = 1;i<=n;i++){
                arr[i] = scanner.nextInt();
            }
            long[] dp = new long[n+1];
            for(int i = 1;i<=n;i++){
                dp[i] = dp[i-1]+arr[i];
            }
            while(q>0){
                int l = scanner.nextInt();
                int r = scanner.nextInt();
                System.out.println(dp[r]-dp[l-1]);
                q--;
            }
        }

}
